Pavement leveling machine having hydraulically snubbed cutter head



Sept. 28, 1965 c. w. HATcHER 3,208,795

PAVEMENT LEVELING MACHINE HAVING HYDRAULICALLY SNUBBED CUTTER HEAD 3 Sheets-Sheet l Original Filed NOV. 5, 1961 CECIL W. HATCHER INVENTOR ATTORNEY Sept. 28, 1965 c. w. HATCHER 3,208,796

PAVEMENT LEVELING MACHINE HAVING HYDRAULICALLY SNUBBED CUTTER HEAD Original Filed Nov. 3, 1961 5 Sheets-Sheet 2 2T' 49 .f e

CECIL w. HA'TCHER INVENTOR l ATTORNEY Sept. 28, 1965 c. w. HATCHER 3,208,796

PAVEMENT LEVELING MACHINE HAVING HYDRAULICALLY SNUBBED CUTTER HEAD 5 Sheets-Sheet 5 Original Filed Nov. 3, 1961 YEAH/Mmmmm CECIL W. HATCHER INVENTOR ATTORNEY United States Patent O 3 208 796 PAVEMENT LEVELING li/IACHINE HAVING HY- DRAULICALLY SNUBBED CUTTER HEAD Cecil W. Hatcher, West Covina, Calif., assignor to Concut,

Inc., El Monte, Calif., a corporation of California Original application Nov. 3, 1961, Ser. No. 150,039.

Divided and this application Apr. 11, 1963, Ser. No.

3 Claims. (Cl. 299-39) This application is a division of application Serial No. 150,039 led November 3, 1961.

The invention relates to a bump cutter with means for reducing eifect of bumps and more particularly it relates to a self-propelled vehicle having rotatable abrasive wheels for removing bumps from concrete paving such as aircraft landing elds, floors and the like.

The invention is an improvement on the bump cutter disclosed and claimed in the following: Pat. No. 3,007,- 687, November 7, 1961, for Concrete Bump Cutter, referred to hereafter as Case A; Pat. No. 3,037,755, June 5, 1962, for Concrete Bump Cutter, referred to hereafter as Case B; Pat. No. 3,087,712, April 30, 1963, for Steering Control for Self-Powered Cutting Machine, division of Case B which is a continuation of Case A, referred to hereafter as Case C. f

In Case A the sensitivity of the machine is reduced to relatively minor irregularities of the surface of the paving by supporting the cutter, for height adjustment, on an elongated frame having a wheel support at a longer distance from the cutter than its vehicle support, whereby the variation in the height of the cutter is only a fraction of the variation in the height of the outer end of such elongated frame as its front wheel rides over the paving.

In Case B the invention is directed to an arrangement wherein the rear of the vehicle frame is pivotally connected to a truck having front and rear wheels which in fact are driving wheels, the truck thus acting as a rear extension frame somewhat of the same general nature as the front extension frame, to reduce the vertical motion at the rear of the vehicle frame in proportion to the lever arms between the front and rear wheels of the truck and the truck pivot.

In Case C the invention is directed to an improved remote steering control for the self-powered cutting machine.

For reasons explained in connection with Cases B and C, it is important to reduce the error in the height of the cutter following the action of the front wheels, noting that while the front wheels reduce the error, they do not eliminate it, for the reason that such error is retiected into the action of the rear wheels to cause a fur-ther error in the height of the cutter. In other words, the accuracy with which the height of the cutter is maintained depends on the combined action of both the front and rear wheel supports. It has been found that the accuracy also depends upon the presence or absence of chattering of the cutter.

The present invention has for an object to further improve the accuracy with which the level of the cutter is maintained. This is accomplished by providing a hydraulic cylinder and control for snubbing or holding down the cutter to its work, or for raising the cutter head from its work. Application S.N. 272,413, led Apr. l1, 1963, discloses and claims the feature of providing an improved bump reducing support for the front wheel suspension for the extension frame. Application S.N. 150,039, tiled November 3, 1961, for Bump Cutter With Means for Reducing Effect of Bumps, of which the present application is a division, discloses and claims the feature of providing an improved rear wheel suspension wherein a CII Patented Sept. 28, 1965 bump at one side of the machine is not reflected into the undesired movement of the other side of the machine, the width of the cutter head being preferably greater than the width of the rear wheels. Preferably the motor for operating the cutter shaft is mounted on the rear of the extension frame, the hydraulic cylinder and piston being connected at their opposite ends to the vehicle frame and the extension frame, with means for supplying fluid pressure to the opposite ends of the cylinder, the pressure when supplied to one end of the cylinder acting to raise the cutter head from its work, and when supplied to the other end of the cylinder, rigidifying the vehicle and extension frames to apply the maximum available weight to the cutter to snub the cutter and hold it down to its work. Preferably the hydraulic cylinder has a separate control for the alternative operation of lifting the :cutter from its work, with coarse and fine controls for the snubber inlet and for the raise out inlet.

For further details of the invention, reference may be made to the drawings wherein FIG. 1 is a view in side elevation of a bump cutter according to the present invention.

FIG. 2 is an enlarged sectional view on line 2 2 of FIG. 1.

FIG. 3 is a sectional view on line 3 3 of FIG. 2.

FIG. 4 is an enlarged sectional View on line 4-4 of FIG. 1.

FIG. 5 is a sectional view on line 5 5 of FIG. 4.

FIG. 6 is a ow diagram of the hydraulic control mechanism employed in connection with the invention.

Referring in detail to the drawings, the vehicle 1 has a vehicle frame 2 at the front end of which is rotatably mounted a cutter head 3 on a cutter shaft 4 having a pulley 5 connected by belt 6 to the pulley 7 on the engine 8. Cutter head 3 comprises a series of abrasive discs on the cutter shaft with separators for leaving a series of ridges in the pavement, or the abrasive discs may be spaced close enough to make a substantially smooth cut. The engine 8 as shown at 9 is mounted on the rear end of an extension frame 10. Extension frame 10 as shown in FIG. 2 has opposite arms 11 and 12, being somewhat U shaped. The rear end of the extension frame 10 has a hinge connection on a horizontal axis, as shown -at 13, with an upright post 14 at each side of the vehicle frame 2, one of these posts being shown in FIG. 1 at 14.

The front end of extension frame 10 has hinge connection 15 on a horizontal axis with the front truck 16 which has a rear caster wheel 17 and a front wheel 18 for steering. The hinge connection 15 includes suitable bearings 19 on the frame 10, the bearing 20 on the truck 16 and a hinge pin or shaft 21.

The front wheel 18 has an axle 22, see FIG. 3, carried by a bracket 23 fixed to a vertical shaft 24 having a bearing 25 on the body 26 of the truck and a further bearing 27 in a housing 28 iixed to the body 26.

The shaft 24 at its upper end has a worm wheel 29 meshing with a worm 30 rotatably supported on a horizontal axis by bearings 31 and 32 carried by the casing 28. The worm 30 is connected by a universal coupling 33 to a short steering rod section 34, the latter having a connect-ion through the universal coupling 35 with the front end of the inclined steering rod 36. Steering rod 36 has bearing supports on the extension frame 10 as indicated at 37, 38 and 39. Bearing 39 is a self-aligning bearing having a swivel mount to permit steering rod 36 to pivot about hinge 13 while the steering rod is supported from vehicle frame 2 by bearing 39. The rear end of extension rod 36 has a handle or steering wheel 40 accessible to an operator for whom a seat 41 is provided, this seat being mounted as shown at 42 on the vehicle frame 2.

As the front of the extension frame 10, which deter- 3 mines the height of the cutter head 3 as described later, is mounted by the hinge connection 15 at an intermediate point on the front truck 16, any bump encountered by the forward travel of the front wheel 18 will be reduced in -its effect on the extension frame in proportion to the relative distances involved between thev hinge connection and the wheels 17 and 18.

The effect of. bumps at the rear of the machine during its forward travel, is reduced as follows:

The rear of the vehicle frame 2 issupported by a rear truck 43 which is composed of two truck members 44 and 45` arranged side by side, see FIG. 4.

Truck member 45 has front and rearI driven wheels 46 and.47 having axles 48 and-49 having bearing supports 51, 52 and 53, 54 on the truck frame 55. Axle 48 has a sprocket 56 and axle 49 has a sprocket 57. Similarly, the other truck member 44 has a truck framek 58 having bearings 59 and 60 for axle 61 of rear driven wheel62. Also, truck frame 58 has bearings 63, 64 for the axle 65 of front driven wheel 66. Axle 61 has a sprocket 67 andl axle 65' has a sprocket 68.

A drive shaft 70 extends across the middle of. both of the truck members 44 and 45 having a sprocket 71 connected by chain 72 to sprocket 56, also having a sprocket 73 connected` by chain 74 to sprocket 57, also having a sprocket 75 connected by a chain 76 to sprocket 68, a sprocket 7.7 connected by chain 78.to sprocket 67, anda central sprocket 79 connectedv by chain 80, see FIGS. l and 4, toa gear box 81, see FIGS. l and 6, which is driven by the hydraulic motor 82.

In FIG..4, the line 113 shows that the width of the cutter head 3 in an. axial direction is greater, viz,I 24 inches, than. the width to the outside edges of the wheels of truck 43, viz., 23 inches. The wheels of the truck 43 thus ride on the path cut by the cutter head 3.

The vehicle frame 2 has laterally spaced side arms 83 84, see FIG'. 4,the rear ends of which are supported by bearings 85 and.86 on the oppositeends 87 and 88.of, the drive shaft 70 which thus serves as a hinge connection for they rear end of the vehicle frame 2', at a horizontal axis intermediate the front'and rear wheels ofthe truck members 44 and 45. Boththe hinge connection just described for the rear end of vehicle frame 2V and the use of individual truck members 44 and 45 contribute to reducing the effect on the cutter vhead 3. of bumps encountered by the rear truck 43 as the vehicle moves in a forward direction.

As shown in FIG. 1, a hydraulic cylinder 9.0, see also FIG. 6, has a hinge connection 91 with the extension frame 10, and having a piston 92 and plunger 93 having a hinge connection 94 with a U shaped bracketl 95, which has opposite vertical arms connected tothe front end of the arms 83' and 84. of the vehicle frame 2, one of these arms. 96 which arises from the front arm 83 whichappears in FIG. 1. Also, the bracket 95 has an adjustable stop 97v to limit the downward movement of, and determine the height of the cutter head 3. As described in connection with FIG. 6, meansare provided for supplying hydraulic pressure tothe opposite ends of cylinder 90, to either raise the cutter head 3, or tovuse the entire weight of thevehicle 1 asa buttress to snub the cutter head 3 andv hold it to its work.

Turning of. FIG. 6 of the drawings, diagrammatically illustrated therein is a hydraulic system which, considered generally,includes a reservoir 98, a hand pump 99 for delivering uid torone end of the cylinder 90 to snub the, cutter head 3 down-in engagement with the pavement, a gear pump 105 having its inlet connected to the reservoir, a two-way valve 106 for deliveringuid from the pump 105 to thek other end of the cylinder 90 through conduit 118 to lift the cutter head clear of the pavement, a threeway valve 109 for delivering fluid from the pump 105 to the hydraulic motor 82 through conduits 123 or 12.4, selectively, to drive the motor in one direction or the other to cause it to drive the vehicle 1 forwardly or rearwardly, and an adjustable relief valve 112 for controlling the Huid pressure of fluid to the hydraulic motor 82 irrespective of the direction in which it is driven. Fluid dumped by relief valve 112 flows through the conduit extending downwardly therefrom to conduit 121 and back to reservoir 98. The hand pump 99 and the valves 106, 109 and 112 are so located that they are readily accessible from the operators seat 41.

v Considering the hydraulic system in more detail, the hand pump 99 is of the reciprocating type and includes a plunger 113 reciprocable by a pivoted handle 100, the cylinder, not shown, in which the plunger 113 is reciprocable being provided with anV inlet check valve, not shown, which communicateswith t he reservoir 98 through a line 104, and being equipped with an outletcheck valve, not shown, which communicates through a line 101 with a snubber port 102 adjacent the. upper end of the cylinder 950. Manual operation of the pump 99delivers fluid from the reservoir 98 to the cylinder 90 above the piston 92 through the lines 104 and 101 to snub the cutter head 3 downwardly against the pavement. The outlet check` valve associated with the plungerY 113 locks the cutter head. 3 in. its snubbed condition. As will be apparent, snubbing the cutter head 3 in this manner locks the vehicle and extension frames. 2 andy 10 together,l and makes themineffect a single rigid frame,yto apply the maximum possible weight tothe cutter head 3 to maintain it in engagement with the pavement without chattering.

When it is desired to release the snubbing action, a relief valve 103 is opened to connect the line 101 to lines 114 and 115 leading to the reservoir 98.

The valve 106 is operated by a handle 107. When it is in one position, other than neutral,.it delivers fluid to a line 118 leading to a cutter head' lifting port 108. When it is desired to lower the cutter head 3relief valve 119 is opened and fluid is returned. to the reservoir 98 by. Way of lines 118, 120, 121,111 and 115. When the valve 106 is in its neutral position, it permits fluid from the pump to flow to the valve 112 andlt-o the valve 109.

IThe valve 109 is a three-way valve operable by a handle'110. When the valve 109 is in a neutral position, it receives fluid from the pump 105 through the line 116, and returns it to the reservoir 98 through a line 122 and the lines 111 and. 115. Under such conditions, the hydraulic motor 82 is inoperative and the vehicle 1 is stationary.

To drive the vehicle 1 in the forward direction, the valve 109 is place in an yoperating position such that fluid under pressure from the pump 105 is delivered to one side of the hydraulic motor 82 .through a line 123., the spent fluid being returned to the reservoir through a line 124 and the line 122,111 andV 115. Conversely, when itis desired to propel the vehicle 1 in the reverse direc tion, the valve 109 is set in a position to deliver iluid under pressure from the. pump 105 to the opposite side of the hydraulic motor 82 through the line 124. Under such conditions, spent fluid is -return to the reservoir through the lines 123, 122, 111 and 115.

' I claim:

1. In a self-propelled, vehicle-type, pavement-cutting machine, the combination of (a) frame means comprising rear main and front extension frames each having front and rear-ends;

(b) means pivotally connecting said rear end of said extension framev to said main frame, rearwardly of said front endof saidmain frame, for relative pivotal movement about a transverse horizontal axis;

(c) rear wheel means connected to said` main frame adjacent the rear end thereof and providing for pivotal movement of saidmainframe about a transverse horizontal axis;

(d) front wheel means located forwardly of the front end of said main frame and connected to and supporting said extension frame adjacent the front end thereof;

(e) rotary cutter means mounted on said main frame adjacent the front end thereof and rotatable about a transverse horizontal axis;

(f) means on said frame means and connected to said rotary cutter means and said rear wheel means for driving said rotary cutter means and for propelling the machine; and

(g) variabe-length means interconnecting said main frame adjacent the front end thereof and said extension frame intermediate the front and rear ends thereof for snubblng said rotary cutter means against upward movement relative to said extension frame.

2. In a self-propelled, vehicle-type, pavement-cutting machine, the combination of:

(a) frame means comprising rear main and front extension frames each having front and rear ends; (b) means pivotally connecting said rear end of said extension frame to said main frame, rearwardly of said front end of said main frame, for relative pivotal movement about a transverse horizontal axis;

(c) rear wheel means connected to said main frame adjacent the rear end thereof and providing for pivotal movement of said main frame about a transverse horizontal axis;

(d) front wheel means located forwardly of the front end of said main frame and connected to and supporting said extension frame adjacent the front end thereof;

(e) rotary cutter means mounted on said main frame adjacent the front end thereof and rotatable about a transverse horizontal axis;

(f) means on said frame means and connected to said rotary cutter means and said rear wheel means for driving said rotary cutter means and for propelling the machine; and

(g) variable-length, bidirectionally-acting means interconnecting said main frame adjacent the front end thereof and said extension frame intermediate the front and rear ends thereof for snubbing said rotary cutter means against upward movement relative to said extension frame, and for moving the front end of said main frame upwardly relative to said extension frame to lift said rotary cutter means clear of pavement over which the machine runs.

3. In a self-propelled, vehicle-type, pavement-cutting machine, the combination of:

(a) frame means comprising rear main and front eX- tension frames each having front and rear ends; (b) means pivotally connecting said rear end of said extension frame to said main frame, rearwardly of said front end of said main frame, for relative pivotal movement about a transverse horizontal axis;

(c) :rear wheel means connected to said main frame adjacent the rear end thereof and providing for pivotal movement of .said main frame about a transverse horizontal axis;

(d) front wheel mans located forwardly of the front end of said main frame and connected to and supporting said extension frame adjacent the front end thereof;

(e) rotary cutter means mounted on said main frame adjacent the front end thereof and rotatable about a transverse horizontal axis;

(f) means on said frame means and connected to said rotary cutter means and said rear wheel means for driving said rotary cutter means and for propelling the machine; and

(g) variable-length, bidirectionally-acting means, comprising a double-acting Huid motor of the reciprocating type, interconnecting said main frame adjacent the front end thereof and said extension frame intermediate the front and rear ends thereof for snubbing said rrotary cutter means against upward movement relative to said extension frame, and for moving the front end of said main frame upwardly relative to said extension frame to lift said rotary cutter means clear of pavement over which the machine runs.

References Cited by the Examiner UNITED STATES PATENTS 1,791,865 2/31 Fordyce. 2,197,549 4/ 60 Hargrave et al. 2,782,017 2/57 Lewis. 3,007,687 11/ 61 Hatcher. 3,107,460 10/ 63 Staehlin.

CHARLES E. OACONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner. 

1. IN A SELF-PROPELLED, VEHICLE-TYPE, PAVEMENT-CUTTING MACHINE, THE COMBINATION OF: (A) FRAME MEANS COMPRISING REAR MAIN AND FRONT EXTENSION FRAMES EACH HAVING FRONT AND REAR ENDS; (B) MEANS PIVOTALLY CONNECTING SAID REAR END OF SAID EXTENSION FRAME TO SAID MAIN FRAME, REARWARDLY OF SAID FRONT END OF SAID MAIN FRAME, FOR RELATIVE PIVOTAL MOVEMENT ABOUT A TRANSVERSE HORIZONTAL AXIS; (C) REAR WHEEL MEANS CONNECTED TO SAID MAIN FRAME ADJACENT THE REAR ENDS THEREOF AND PROVIDING FOR PIVOTAL MOVEMENT OF SAID MAIN FRAME ABOUT A TRANSVERSE HORIZONTAL AXIS: (D) FRONT WHEEL MEANS LOCATED FORWARDLY OF THE FRONT END OF SAID MAIN FRAME AND CONNECTED TO ANDN SUPPORTING SAID EXTENSION FRAME ADJACENT THE FRONT END THEREOF; (E) ROTARY CUTTER MEANS MOUNTED ON SAID MAIN FRAME ADJACENT THE FRONT END THEREOF AND ROTATABLE ABOUT A TRANSVERSE HORIZONTAL AXIS; (F) MEANS ON SAID FRAME MEANS AND CONNECTED TO SAID ROTARY CUTTER MEANS AND SAID REAR WHEEL MEANS FOR DRIVING SAID ROTARY CUTTER MEANS AND FOR UPROPELLING THE MACHINE; AND (G) VARIABLE-LENGTH MEANS INTERCONNECTING SAID MAIN FRAME ADJACENT THE FRONT END THEREOF AND SAID EXTENSION FRAME INTERMEDIATE THE FRONT AND REAR ENDS THEREOF FOR SNUBBING SAID ROTARY CUTTER MEANS AGAINST UPWARD MOVEMENT RELATIVE TO SAID EXTENSION FRAME. 